The present inventive concept relates to non-volatile memory devices. More particularly, the inventive concept relates to non-volatile memory devices capable of randomizing data and then storing the randomized data, as well as related operating methods.
Non-volatile memory devices include flash memory, resistance variable memory devices, and the like. Flash memory may be divided into NAND flash memory and NOR flash memory. NOR flash memory is characterized by a structure in which memory cells are connected in parallel to a bit line. This parallel connection allows the memory cells of NOR flash memory to be accessed randomly. In contrast, NAND flash memory is characterized by a structure in which memory cells are connected in series to a bit line. That is memory cells in NAND flash memory are connected in a string of memory cells, thereby requiring only a single connection contact with the bit line. As a result, NAND flash memory may be very densely integrated.
In recent years, research has been conducted related to a technique whereby a plurality of data bits may be stored in a single non-volatile memory cell, thereby providing a greater degree of data storage capacity per unit area of the flash memory device. A memory cell capable of storing a plurality of data bits is commonly referred to as a multi-level cell (MLC). In contrast, a memory cell capable of storing only a single data bit is commonly referred to as a single-level cell (SLC). In general, a MLC is characterized in its programming capabilities by the use of two or more threshold voltage distributions, each being related to a particular data state.